Composite iron golf club

Abstract: An iron golf clubhead includes a blade (11) which is formed from a first material and a hosel (12) and a junction portion (13) which are formed from a second material which is less dense than the material of the blade. The blade includes a toe end and a heel end and a flat bracket (26) which extends from the heel (32) end. The junction portion (13) surrounds the bracket (26) and is secured thereto.

Description: This invention relates to an iron type golf clubhead according to the preamble of claim 1. An iron clubhead includes a blade, which includes the club face for striking a golf ball, and a hosel, to which the shaft is secured. A junction portion connects the hosel and the blade. Iron clubheads are conventionally forged or cast in a single, integral piece from metal or metal alloy. Some clubheads are formed from two or more different materials. For example, a metal core can be covered with fiber-reinforced composite material, or the face and back of the clubhead can be formed from different materials. In such cases, however, the hosel and junction are generally formed integrally with a portion of the blade. The GB-A-2 192 795 discloses a composite golf club iron head comprising a hosel for attaching the head to a shaft, a front surface defined by a heel, a sole, a toe, a topline and a backweight. The hosel, heel and a portion of the toe form a unitary member and are made of a material of a first weight density; the sole, backweight, remainder of the toe and a majority of the front surface are -- as a second unitary member -- formed of a material of a second weight density, said second weight density being higher than said first weight density, whereby the weight distribution of said head is greatest adjacent the centre of said front surface. The said first unitary member is made of epoxy-impregnated graphite, and the second unitary member is made of steel. This iron clubhead is said to provide better durability, a better weight distribution, a better utilisation of the mass of the head and better control of the location of the centre of gravity which tends to reduce the likelihood of an errant shot. Each numbered golf iron, for example a 5 iron, has a standard weight which does not vary much between various manufacturers of golf clubs. A typical iron clubhead has about 78% of its weight in the blade area and about 22% of its weight in the junction area. Ball flight and distance is affected by the weight of the blade and the manner in which the weight is distributed in the blade. The weight in the hosel and the junction area has little or no effect on the ball. Some clubs have redistributed weight from the hosel to the blade by forming openings or cutouts in the hosel. However, such openings interrupt the integrity of the hosel. Other clubs have reduced the length of the hosel or eliminated the hosel. However, the attachment of the shaft to the clubhead can be adversely affected. The invention refers to a composite iron clubhead in which the blade -- including a toe end and a heel end --is formed of a first material and the hosel and hosel junction are formed from a second material which is less dense than the first material. Weight is thereby taken out of the hosel and injunction and redistributed to the blade. The additional weight in the blade will have an advantageous effect on the flight and distance of the golf ball. The innovation comprises a relatively flat bracket which extends from the heel end of the blade and which is thinner than the blade at the heel end, the junction portion surrounding the bracket and being secured thereto. This bracket is provided with openings through which the material of the junction portion extends. The said bracket includes curved top and bottom edges. One embodiment of the invention shows a clubhead in which the face is provided with parallel grooves which extend between the toe end and heel end of the blade, each groove having a toe end and a heel end, the heel end of the blade extending substantially perpendicularly to the heel ends of the grooves and being spaced about 2,54 to 5,08 mm (0.10 to 0.20 inch) from the heel ends of the grooves. In addition it is found good that the heel end of the blade is spaced about 3,81 mm (0.15 inch) from the heel ends of the grooves. The weight of the blade should be from about 85 to 95 % of the total weight of the clubhead and the weight of the hosel and junction portion from abort 5 to 15 % of the total weight of the clubhead. The invention will be explained in conjunction with an illustrative embodiment shown in the accompanying drawing, in which Fig. 1 is a front elevational view of a clubhead formed in accordance with the invention; Fig. 2 is a rear elevational view of the clubhead; Fig. 3 is a front elevational view of the blade of the clubhead; Fig. 4 is a rear elevational view of the blade; Fig. 5 is a side elevational view of the blade taken along the line 5-5 of Fig. 3; Fig. 6 is a view similar to Fig. 2 with the junction portion of the clubhead broken away; and Fig. 7 is a view similar to Fig. 2 showing the bracket of the blade in dotted outline. Referring first to Fig. 1 and 2, an iron type golf clubhead 10 includes a blade 11, a hosel 12, and a junction 13 which joins the hosel 12 and the blade 11. The hosel 12 is tubular or cylindrical and is provided with a bore 14 which is adapted to receive a conventional golf club shaft. The shaft is inserted into the hosel 12 and secured therein in the conventional manner. The blade 11 includes a toe end 15 and a heel end 16 and a flat face 17 which extends from the toe end 15 to the heel end 16. A plurality of parallel grooves 18 are formed in the face 17 in the conventional manner. The blade 11 also includes a top edge 19, a sole 20, and a back surface 21. The particular clubhead 10 illustrated includes a cavity 22 in the back surface. The bottom of the junction 13 curves upwardly from the sole of the blade 11, and the top of the junction 13 includes a generally U-shaped notch 23. The grooves 18 are usually designed so that they extend parallel to a ground plane G when the center of the sole rests on the ground in the proper address position. The toe ends of the grooves 18 and the heel ends of the groove 18 are aligned along lines which extend perpendicularly to the grooves 18. Referring now to Fig. 3 to 5, the blade 11 is formed separately from the junction 13 and the hosel 12. The heel end 16 of the blade 11 terminates in a flat end surface 25 which extends perpendicularly to the face 17 and the grooves 18. A flat, thin bracket 26 extends from the end surface 25 parallel to the face 17. As can be seen in Fig. 5, the thickness of the bracket 26 is constant along the length of the bracket 26 and the thickness of the bracket 26 in a direction perpendicular to the face 17 is less than the thickness of the blade 11 along the top edge 19. The bracket 26 has a curved bottom edge 27 and a U-shaped top edge 28 which conform generally to the contour of the junction 13. The bracket 26 terminates in a straight end edge 29. A plurality of openings 30 are formed in the bracket 26. The blade 11 can be formed by conventional forging or casting techniques. The bracket 26 is formed integrally with the remainder of the blade 11, and, if necessary, suitable finishing operations can be performed on the bracket 26 to obtain the desired shape or openings 30. In the embodiment illustrated, the entire bracket 26 is generally planar and extends parallel to the face 17. However, for irons which have an offset hosel 12, the bracket 26 can curve forwardly beyond the face 17 so that the completed hosel 12 will have the desired offset relative to the blade 11. The material of the junction 13 and hosel 12 is cast or otherwise formed around the bracket 26 and abuts the flat end surface 25 of the blade 11. During formation of the junction 13, the molten or soft material of the junction 13 flows through the openings 30 in the bracket 26 to form a secure interconnection between the junction 13 and the bracket 26. The bore of the hosel 12 may be formed while the hosel 12 is formed and extends substantially to the end 29 of the bracket 26. Alternatively, the material of the junction 13 and the hosel 12 can be joined to the blade 11 at the surface 25 by welding, brazing, epoxy, copper flash, or mechanical fit. The outer surface of the junction 13 merges smoothly with the outer surface of the blade 11, and a seam line 32 is formed where the material of the junction 13 meets the material of the blade 11. If desired, the seam line 32 can be buffed to render the seam less perceptible. The seam line 32 extends perpendicularly to the grooves 18. The flat end surface 25 and the seam line 32 are spaced about 2,54 to 5,08 mm (0.10 to 0.20 inch), preferably about 3,81 mm (0.15 inch), from the heel ends of the grooves 18 and are substantially aligned with the intersection P (Fig. 1) between the axis or centerline CL of the hosel 12 and the ground plane G. The blade 11 is formed from a relatively dense material, and the junction 13 and hosel 12 are formed from a less dense material so that the weight of the junction 13 and hosel 12 is less than the weight of the junction 13 and hosel 12 of a conventional club. The weight of the blade 11 can therefore be increased while maintaining the overall weight of the clubhead within the traditional range. The extra weight in the blade 11 can be used to increase the perimeter weighting of the cavity-backed blade 11 and/or increase the mass behind the sweetspot of the face 17. The material of the blade 11 can be corrosion resistant stainless steel, beryllium copper alloy, or other conventional clubhead materials. The material of the hosel 12 and junction 13 can be aluminum, titanium, composite material such as fiber reinforced resin, e.g., graphite fibers and epoxy resin, or other material which is lighter than the material of the blade 11. A typical number iron clubhead 10 has about 78-80% of its weight in the blade area and about 20-22% of its weight in the hosel 12 and junction 13 area. By forming the clubhead 10 in accordance with the invention, the weight distribution of the clubhead 10 can be changed so that a substantially higher percentage of the weight of the clubhead 10 is in the blade 11. For example, the weight distribution can be varied as desired so that from 80% to up to about 95% of the weight is in the blade 11 and only about 20% to 5% is in the hosel 12 and junction 13 area. More preferably, the weight of the blade 11 is between about 85 and 95% of the total weight of the clubhead 10, and the weight of the hosel 12 and junction 13 is between about 5 and 15% of the total weight. Even more preferably, the weight distribution is about 90% of the blade 11 and about 10% in the hosel/junction area. Table I describes the weight distribution of a prior art set of conventional Wilson Ultra iron clubheads. Conventional Clubhead No. of Iron Total Weight (grams) weight in Blade (grams) Weight in Hosel/Junction (grams) % of Weight in Blade % of Weigh in Hosel 1 236.2 185.3 50.9 78.45 21.55 2 242.3 191.55 50.75 79.05 20.95 3 247.2 195.5 51.7 79.09 20.91 4 253.8 200.7 53.1 79.08 20.92 5 258.5 202.9 55.6 78.49 21.51 6 266.3 212.5 53.8 79.80 20.20 7 271.4 216.25 55.15 79.68 20.32 8 279.2 220.70 58.5 79.05 20.95 9 286.7 226.25 60.45 78.92 21.08 PW 296.4 235.05 61.35 79.32 20.20 Sand Wedge 322.9 253.8 69.1 78.60 21.40 60° Wedge 315.2 245.35 69.85 77.84 22.16 By varying the materials which are used for the blade 11 and for the hosel 12 and junction 13, the weight distribution in the blade 11 and the hosel/junction 12/13 can be varied as desired while maintaining the overall weight of the clubhead 10 within the standard range. For example, the clubheads in Table I were made from steel which has a density of 7,75 g/cm 3 (0.28 pounds per cubic inch). An advantageous material for the hosel/junction area is A206 aluminum, which has a density of only 2,768 g/cm 3 (0.101 pounds per cubic inch). Dimensions and weights which are referred to herein may vary within standard manufacturing tolerances for cast and forged clubheads, for example about ± 2%.

Claims: An iron type golf clubhead having a blade (11), a hosel (12), and a junction portion (13) which joins the blade and the hosel, the blade having a toe end (15) and a heel end (16) and a face (17) for striking a golf ball, the blade being formed from a first material and the hosel being formed from a second material which is less dense than the first material, characterized in that the blade (11) includes a bracket (26) which extends from the heel end (16) and which is thinner than the blade (11) at the heel end, the junction portion (13) surrounding the bracket and being secured thereto. The clubhead of claim 1 in which the bracket (26) is provided with openings (30) through which the material of the junction portion (13) extends. The clubhead of claim 1 or 2 in which the bracket (26) includes curved top and bottom edges (27, 28). The clubhead of one of the claims 1 to 3 in which the face (17) is provided with parallel grooves (18) which extend between the toe end (15) and heel end (16) of the blade (11), each groove having a toe end and a heel end, the heel end of the blade extending substantially perpendicularly to the heel ends of the grooves and being spaced about 2,54 to 5,08 mm (0.10 to 0.20 inch) from the heel ends of the grooves. The clubhead of claim 4 in which the heel end (16) of the blade (11) is spaced about 3,81 mm (0.15 inch) from the heel ends of the grooves (18). The clubhead of one of the claims 1 to 5 in which the bracket (26) is substantially flat. The clubhead of one of the claims 1 to 6 in which the weight of the blade (11) is from about 85 to 95 % of the total weight of the clubhead (10) and the weight of the hosel (12) and junction portion (13) is from about 5 to 15 % of the total weight of the clubhead.

Inventors: MEYER DEAN E, MEYER, DEAN E.
Applicants: WILSON SPORTING GOODS, WILSON SPORTING GOODS COMPANY
Application year: 1994
Main classification: A63B53
IPC codes: A63B53